Changeset 6b72040 for doc/working

Timestamp:

Jun 2, 2017, 1:10:26 PM (7 years ago)

Author:

Andrew Beach <ajbeach@…>

Branches:

ADT, aaron-thesis, arm-eh, ast-experimental, cleanup-dtors, deferred_resn, demangler, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, pthread-emulation, qualifiedEnum, resolv-new, with_gc

Children:

93684eb

Parents:

acd738aa

Message:

The try exception handler function is now generic.

Location:

doc/working/exception

Files:

• impl/except.c (modified) (3 diffs)
• impl/main.c (modified) (5 diffs)
• reference.c (modified) (1 diff)

doc/working/exception/impl/except.c

@@ -4 +4 @@
 
 #include "lsda.h"
+
+// This macro should be the only thing that needs to change across machines.
+// struct _Unwind_Context * -> _Unwind_Reason_Code(*)()
+#define MATCHER_FROM_CONTEXT(ptr_to_context) \
+        (*(_Unwind_Reason_Code(**)())(_Unwind_GetCFA(ptr_to_context) + 8))
+
 
 //Global which defines the current exception
@@ -17 +23 @@
                      struct _Unwind_Exception* unwind_exception, struct _Unwind_Context* context)
 {
+        printf("CFA: 0x%lx\n", _Unwind_GetCFA(context));
+
         //DEBUG
         printf("Personality function (%d, %x, %llu, %p, %p):", version, actions, exceptionClass, unwind_exception, context);
@@ -111 +119 @@
 
                                         //Get a function pointer from the relative offset and call it
-                                        _Unwind_Reason_Code (*matcher)() = (_Unwind_Reason_Code (*)())lsd_info.LPStart + imatcher;                                      
+                                        // _Unwind_Reason_Code (*matcher)() = (_Unwind_Reason_Code (*)())lsd_info.LPStart + imatcher;                                   
+
+                                        _Unwind_Reason_Code (*matcher)() =
+                                                MATCHER_FROM_CONTEXT(context);
                                         _Unwind_Reason_Code ret = matcher();
 

doc/working/exception/impl/main.c

@@ -1 +1 @@
 #include <stdio.h>
 #include "except.h"
+
+// Requires -fexceptions to work.
 
 #define EXCEPTION 2
@@ -26 +28 @@
 extern int this_exception;
 _Unwind_Reason_Code foo_try_match() {
-        return this_exception == 3 ? _URC_HANDLER_FOUND : _URC_CONTINUE_UNWIND;
+        printf(" (foo_try_match called)");
+        return this_exception == EXCEPTION ? _URC_HANDLER_FOUND : _URC_CONTINUE_UNWIND;
 }
 
@@ -34 +37 @@
 //for details
 __attribute__((noinline))
-void try( void (*try_block)(), void (*catch_block)() )
+void try( void (*try_block)(), void (*catch_block)(),
+          _Unwind_Reason_Code (*match_block)() )
 {
+        volatile int xy = 0;
+        printf("%p %p %p %p\n", &try_block, &catch_block, &match_block, &xy);
+
         //Setup statments
         //These 2 statments won't actually result in any code,
@@ -95 +102 @@
         "       .uleb128 .CATCH-try\n"                          //Hanlder landing pad adress  (relative to start of function)
         "       .uleb128 1\n"                                           //Action code, gcc seems to use always 0
-        //Beyond this point we don't match gcc data'
-        "       .uleb128 foo_try_match-try\n"                   //Handler routine to check if the exception is matched
         ".LLSDACSECFA2:\n"                                              //BODY end
         "       .text\n"                                                        //TABLE footer
@@ -122 +127 @@
 
         //Actual call to the try block
-        try( foo_try_block, foo_catch_block );
+        try( foo_try_block, foo_catch_block, foo_try_match );
 
         printf( "Foo exited normally\n" );
 }
 
+// Not in main.cfa
+void fy() {
+        // Currently not destroyed if the exception is caught in fee.
+        raii_t a = { "Fy dtor" };
+
+        void fy_try_block() {
+                raii_t b = { "Fy try dtor" };
+
+                throw( 3 );
+        }
+
+        void fy_catch_block() {
+                printf("Fy caught exception\n");
+        }
+
+        _Unwind_Reason_Code fy_match_block() {
+                return this_exception == 2 ? _URC_HANDLER_FOUND : _URC_CONTINUE_UNWIND;
+        }
+
+        try(fy_try_block, fy_catch_block, fy_match_block);
+
+        printf( "Fy exited normally\n" );
+}
+
+void fee() {
+        raii_t a = { "Fee dtor" };
+
+        void fee_try_block() {
+                raii_t b = { "Fee try dtor" };
+
+                fy();
+
+                printf("fy returned\n");
+        }
+
+        void fee_catch_block() {
+                printf("Fee caught exception\n");
+        }
+
+        _Unwind_Reason_Code fee_match_block() {
+                return this_exception == 3 ? _URC_HANDLER_FOUND : _URC_CONTINUE_UNWIND;
+        }
+
+        try(fee_try_block, fee_catch_block, fee_match_block);
+
+        printf( "Fee exited normally\n" );
+}
+// End not in main.cfa
+
 int main() {
         raii_t a = { "Main dtor" };
 
-        for (unsigned int i = 0 ; i < 100000000 ; ++i) foo();
+        //for (unsigned int i = 0 ; i < 100000000 ; ++i)
+        foo();
+        fee();
 
         printf("End of program reached\n");

doc/working/exception/reference.c

@@ -114 +114 @@
 // __builtin_eh_return_data_regno(^) ^=[0..3]? gives index.
 
+// Locally we also seem to have:
+_Unwind_Word _Unwind_GetCFA (struct _Unwind_Context *);
 
 // GCC (Dwarf2 ?) Frame Layout Macros
-// https://gcc.gnu.org/onlinedocs/gccint/Frame-Layout.html
+// See: https://gcc.gnu.org/onlinedocs/gccint/Frame-Layout.html
+// Include from: ???
 
 FIRST_PARAM_OFFSET(fundecl)